As a result of the normal operation of an internal combustion engine, carbon and other organic compounds tend to build up on internal surfaces of the engine, as well as in the exhaust system, including the oxygen sensor and catalytic converter. Compositions and methods have been devised that flush engines with cleaning fluid or other types of chemical solvent solutions in an attempt to clean these surfaces. In one such system, a separate canister containing a liquid mixture of engine fuel and injector cleaning solvent is connected to the fuel line, and the engine is operated using the fuel solvent mixture.
The use of such fuel solvent mixtures can be problematic. For example, strong solvents can be corrosive and can damage the internal surfaces of the engine and the oxygen sensor. Additionally, typical conventional solvent and detergent cleaning fluids are mixed with gasoline and the automobile engine is run during cleaning. When these cleaning fluids are successful in dislodging or removing carbon deposits they essentially only move the deposits downstream to the combustion chamber and/or exhaust system. Emissions during such a “cleaning treatment process” are dramatically increased as the carbon and sludge moves further into the engine. Following such treatments, an operator must drive the treated vehicle for a full tank of gas before the vehicle can pass an emissions test.
Another poor aspect of this technology the effect of harmful emissions on the environment. Even though a treatment may only be for 1 h or less per vehicle service, it is estimated that there are millions of vehicles being serviced annually on a global scale and the numbers will continue to expand as electronics grow more sophisticated and prevalent in modern vehicles and the cumulative effect of these emissions is substantial. The exposure of technicians servicing automobiles to the toxic fumes produced during treatment is also problematic. Service technicians are already exposed to hundreds of toxins and harmful chemicals and the known engine cleaning methods and compositions only add to this problem in the service area. In the United States some states have begun to send information encouraging service facilities to cease using some of these chemicals because of the potential effects and possible litigation.
Thus, new engine cleaning methods are needed that can clean engines more thoroughly without leaving deposits downstream of the combustion chamber and that have reduced or no toxic emissions.